A film that spends most of its time explaining the dangers of free soloing and why someone would do it is stating the obvious for climbers. That could be condensed into a minute. Climbing is what we wanted to see, and we got a little of it.
That's true - though even for non-climbers like me, as soon as someone answers your question "What does free solo mean?" you also know the dangers, you don't need to be a climber to get that, haha! I thought the movie was great, but I had my eyes closed for much of the climbing scenes. Even though I knew he made it, obviously, it just made me too queasy to do more than peek here and there to see what he was doing. Obviously, the filmmakers needed the film to be commercially viable. My perspective on the background stuff (girlfriend, relationship with family, etc.) is that it helped me to bond with Alex as a person, and not just see him as some weird freak of nature who thinks only of climbing at the expense of all else.
I admit to an overall feeling of sadness during the movie; he came across as so likeable, smart, and funny that all I could think of is that, talented and careful as he is, if he keeps doing this he is unlikely to live to a ripe old age. And while I always feel sorry when I hear of a climber losing his or her life in a climbing accident, it will almost feel personal to me if something happens to Alex Honnold, because the filmmakers did such a good letting me think I know him (a little bit) as a person, and not just as a real-life Spiderman.
Anyway, agree that climbers would not have been as interested, but for me I thought it was great.